Reverse Osmosis Plant for Dialysis Units

The water used to prepare the dialysis fluid is usually extracted from a drinking water source, such as a municipal water supply. It’s worth noting that this drinking water is not used for dialysis units and requires more advanced treatments to reduce chemical and microbial contamination.

This is simply because dialysis patients are exposed to more water and, consequently, more contaminants that accumulate in their bodies, causing toxicity that can lead to death.

Healthy people consume approximately 14 liters of water per week (i.e., two liters per day). However, a typical dialysis treatment, three times per week for four hours per session, exposes the patient to over 500 liters of water per week. Due to this high exposure to contaminants in the water, such as lead, additional treatment of the water used to prepare the dialysis water is required.

Public drinking water also carries higher levels of pathogens, including bacteria, viruses, and parasites. Therefore, drinking water is unsafe for use in dialysis and must be further treated to reduce chemical and biological contamination. The Role of Water in Hemodialysis

Hemodialysis is a life-saving treatment, and the water used to produce the dialysis fluid must meet established standards. The dialysis fluid used in hemodialysis is essential to the health and well-being of kidney patients, meaning their blood must be cleansed of harmful impurities.

The treated water is mixed with concentrated electrolyte and buffer solutions to produce the dialysis fluid used in this procedure.

To protect dialysis patients from exposure to chemical and microbiological contaminants, international and national standards organizations have published strict quality standards for dialysis fluid.

Hemodialysis Water Quality Standards

These standards have been in existence for more than 25 years. Current standards focus on the maximum permissible levels of chemical and microbiological contaminants, as well as methods for measuring them. For example, dialysis water must be free of fluoride, chlorine, and other chemical and organic contaminants. This is critical to the patient’s health, as these chemicals can accumulate in the body, potentially leading to death.

Dialysis laboratories require a water treatment system that purifies water according to established quality standards to ensure patient safety.

Ensuring Dialysis Water Quality

Experts advise against performing dialysis without a multi-media filter, carbon filtration, single-micron filter, or reverse osmosis (RO) technology. Multi-media filters, ultrafilters, deactivated carbon beds, and filters are used to ensure the quality of dialysis water. However, reverse osmosis plays an important role in ensuring that bacterial and microbial levels remain within specified limits.

High-pressure membrane systems, such as reverse osmosis (RO), help increase the efficiency of contaminant removal. Two-stage or dual-stage reverse osmosis is the most suitable technology for removing pathogens from dialysis water, as it removes organic and inorganic solutes, including microorganisms, viruses, endotoxins, salts, and metals. RO systems have a high rejection rate of 90% to 99%.

Read more about Reverse Osmosis technology

Hemodialysis Water Purification Methods

The hemodialysis water purification process involves several filtration stages to ensure high quality and freedom from contaminants such as particles, elements, chemicals, organic matter, bacteria, and bacterial residues. The water purification process consists of five main stages:

• Preliminary Treatment: This stage includes mixing hot and cold water to a constant temperature, initial filtration, water softening, and adsorption with activated carbon. In some cases, hydrochloric acid may be injected to correct pH levels.
• Water Softening: This stage involves using a water softener to replace calcium and magnesium ions in hard water with sodium ions. This process helps extend the life of the reverse osmosis (RO) membrane.
• Activated Carbon Filtration: In this step, activated carbon filters are used to remove chlorine, chloramines, and other dissolved organic contaminants from the water. Two layers of carbon are often used to ensure complete removal of these substances.
• Reverse Osmosis (RO): This is the primary method of water purification in hemodialysis units. Reverse osmosis uses hydrostatic pressure to force water through a semi-permeable membrane, removing more than 90% of contaminants, including ionic substances, bacteria, and endotoxins.
• Deionization (DI): This process removes ionic contaminants by replacing cations with hydrogen ions. Deionization is typically used as a backup measure in cases of reverse osmosis membrane failure or as an additional purification step. However, deionization systems can promote bacterial growth, necessitating the use of post-purification bacterial control filters. Deionization systems also require continuous conductivity monitoring.

These methods help produce ultra-pure water, which is essential for safe and effective dialysis treatment.

Water Pretreatment and Softening

Before use in a dialysis unit, water undergoes pretreatment to ensure purity and integrity. This process includes mixing hot and cold water to maintain a constant temperature, preliminary filtration, softening, and adsorption with activated carbon. Temperature mixing valves are typically installed to regulate the water feed at 77°F, which enhances the efficiency of the reverse osmosis membrane system.

The softening process is essential for protecting reverse osmosis membranes and extending their lifespan. This process involves using ion exchange to remove positively charged ions. Such as calcium, magnesium, and heavy metals, from the water source and replace them with Sodium ions.

Water softeners play an important role in areas with “hard water,” reducing the buildup of calcium and magnesium salts that can damage the reverse osmosis membrane.

In hemodialysis water purification systems, single- and double-layer softeners are commonly used to achieve effective results. By implementing appropriate pretreatment and softening processes. Hemodialysis units can ensure that water quality is sufficient for safe and effective treatment.

Carbon Adsorption and Filtration

In the hemodialysis water purification process, carbon adsorption and filtration play a vital role in ensuring clean and safe water for patients. Carbon adsorption is a method that uses activated carbon to effectively remove contaminants. Such as chlorine, chloramines, and other dissolved organic compounds, from water. If left untreated, these compounds can pose a significant health risk to patients undergoing hemodialysis treatments.

Carbon adsorption typically consists of two layers of activated carbon to ensure complete contaminant removal. Filtration is an additional step performed using a filter installed just before the reverse osmosis membrane. To capture any residual carbon particles and resin beads that may have been unintentionally released from the pretreatment system. This combination of carbon adsorption and filtration enhances the effectiveness and safety of dialysis water purification systems.

By incorporating these important steps into dialysis water treatment plants, healthcare providers can ensure the provision of high-quality medical-grade water. Reducing the risk of complications and improving patient outcomes. Ultimately, carbon adsorption and filtration significantly improve the health and well-being of those who rely on dialysis.

Conclusion

Finally, the quality of dialysis water must be regularly tested to ensure its quality. These are the basic requirements for dialysis water.

To ensure quality dialysis water, a water treatment plant equipped with dual reverse osmosis systems must be operated. We can assist you in designing and operating such a plant.